273

IV. DTC Display Method

V. HCU Diagnosis

Use the scan meter to diagnose the Hydraulic Control Unit (HCU), select the "3 HCU diagnosis" in the

options and perform the following procedures.

*

Perform the above step 2 - 8 test for each wheel in the following order LF 

 RF 

 LR 

 RR.

*

If the result of some one of the above steps is different from the normal result, it indicates that the

corresponding element fails the normal operation, please check the corresponding element.

*

You can use “ESC” button to end the test to return the function menu in any place in the screen where

there is “return” displayed to return to the function menu.

Code Displayed

Never happened before

No DTC

Happened before

Occasional DTC

Never happened before

Non-occasional DTC

Happened before

Occasional DTC and Non-
occasional DTC

System Problem

There is no problem current ABS

Warning Light does not light up）

The problem still exists（ABS

Warning Light goes on）

Step

Action

Screen Display

Normal Result

1

HCU diagnosis – hydraulic pump test

Pump motor operates

2

LF Wheel——Depress the brake pedal

3

LF Wheel—— normally open valve
open, normally closed valve closed,
wheel locked？

Wheel locked

4

LF Wheel—— normally open valve
closed, normally closed valve closed,
wheel locked？

Wheel locked

5

LF Wheel — — normally open valve
closed, normally closed valve open,
wheel can rotate freely

Wheel can rotate freely, the
pedal rebound, the cylinder

motor operating noise is audible

6

LF Wheel—— normally open valve
closed, normally closed valve closed,
wheel can rotate freely

Wheel can rotate freely

7

LF Wheel — — normally open valve
open, normally closed valve closed,
wheel locked？

Wheel locked, the pedal sag
slightly

8

Release the brake

pedal

Depress and hold

the brake pedal

→

→

→

274

VI. Troubleshooting Quick Index

VII. Non-DTC Problem Inspection Table Index

DTC

Fault Description

Diagnosis Result

Inspection

Table No.

Reference

Page

65535

ECU

Damaged

1276

ABS hydraulic pump

Motor can not operate

1

275

283

LF Wheel Sensor

276

285

RF Wheel Sensor

277

290

LR Wheel Sensor

278

287

RR Wheel Sensor

1044

ABS programming error

5

279

668

Power supply terminal 30

6

280

1130

Abnormal ABS operation Signal is not as specified

7

281

Electrical or mechanical
fault

2,3,4

Inspection

Table No.

Reference

Page

1

282

2

283

The brake force on both sides is not uniform
The brake force is insufficient
ABS operates when the brake pedal is slightly
depressed（vehicle is stationary）
ABS operates when the brake pedal is slightly

depressed（vehicle is driving）
When the ABS operates, the brake pedal vibrates
severely

4

285

5

286

6

287

No DTC output（failure in communicating with the scan meter）

Fault Status

Turn the ignition switch to “ON” (With engine off), ABS Warning
Light does not go on

After the engine is started, the warning light does not go off

ABS

abnormal

284

3

 Brake pedal stroke is excessively long

You need to heavily depress the brake pedal

275

VIII. ABS ECU Connector Pin Layout

ABS ECU Connector (End Views)

Electrical Wiring Diagram

Combination Meter

ABS Warning Light 

Drive Module

ABS ECU

ABS RR Wheel Sensor

ABS LR Wheel Sensor

ABS RF Wheel Sensor

ABS LF Wheel Sensor

Brake Lamp Switch

276

Section 2 ABS System Check

I. DTC Problem Inspection Table

Note: If the Battery is excessively discharged, the motor will not be driven, therefore you must

check that the battery voltage is normal before performing the motor driving test. The vehicle

must be stationary during the test.

  1    DTC 01276

Like ly Caus e s

[De s cription] 

When the vehicle speed exceeds

20km/h, ABS ECU detects that the motor can not

operate normally and record this DTC.

[Hint]

 When this problem occurs, one of the

possible causes is that the wire harness between

the motor and the ECU is disconnected. Use the

scan meter to perform the test by activating the

HCU function to drive the motor.

 

Power supply is disconnected or grounded

 

Motor wire harness is disconnected

 

Motor is damaged

Remove the motor wire harness connector, connect

it to the Battery to see whether the motor operates?

Check the fuse and ABS ECU connector

Connect the motor wire harness connectorTurn the

ignition switch to ONClear the DTC Use the scan

meter to Perform the HCU diagnosistor

Turn the ignition switch to ON

Does the fault reoccur?

Refer to “Occasional Problem Service Key Point”

 

 

 

 

Normal

Normal

No

Abn.

Abn.

Yes

Replace the HCU

Replace the fuse or wire harness

Replace the ECU